The goal of the proposed research is to evaluate the metabolic role for the human lens arylamidase, esterase I, dipeptidyl aminopeptidase I, cataractous protease, Waley's neutral proteinase and the crystalline leucine aminopeptidase, identifying precise bonds, peptides, and transfer reactions occurring in the aging lens, the cataractous lens, the transformation of the epithelial cell into the lens fiber, proteolipidolysis and insolubilization of lenticular proteins. To learn the localization of hydrolytic enzymes within the different regions or organelles in the lens. To determine the possible relationship of the loss of low molecular weight soluble proteins with the increase in insoluble proteins in nuclear cataractous lenses. To compare isolated enzymes from human lens with the well characterized proteolytic enzymes of digesting secretion. BIBLIOGRAPHIC REFERENCES: Investigations of Proteolytic Activity in Bovine Lenses with Age. I. Exopeptidases. A.A. Swanson, U. Hahn and O. Hockwin. Documenta Ophthalmologica Proceedings Series special issue - dedicated to Professor Jean Nordmann. Documenta Ophthalmologica Proceedings Series. Progress of Lens Biochemistry Research, 135-144 (1977). Studies on Proteolytic Activity in Bovine Lenses with Aging. II. The Endopeptidases. O. Hockwin, U. Hahn and A.A. Swanson. Ophthalmic Research 1977, in press.